In a power supply device disclosed in Patent Literature 1, the output of a rectifier circuit is branched into a plurality of current paths, and a plurality of series circuits are provided in parallel, each of which is configured by a reactor and a switching element. When the switching element is off, a current in the reactor provided in each of the series circuits is supplied to a smoothing capacitor via a backflow prevention diode. The switching elements provided in the respective series circuits are driven individually at a different phase. Due to this operation, a current that flows via each of the switching elements is suppressed, and also ripple components in a current output from each of the reactors are suppressed.